3,3′-Diethyl-1,1′-(1,4-phenyl­ene­dimethyl­ene)diimidazol-3-ium bis­(hexa­fluoro­phosphate)

Rosenani A Haque; S Fatimah Nasri; Mohd Mustaqim Rosli; Hoong-Kun Fun

doi:10.1107/S1600536812028966

. 2012 Jun 30;68(Pt 7):o2280. doi: 10.1107/S1600536812028966

3,3′-Diethyl-1,1′-(1,4-phenylenedimethylene)diimidazol-3-ium bis(hexafluorophosphate)

Rosenani A Haque ^a, S Fatimah Nasri ^a, Mohd Mustaqim Rosli ^b, Hoong-Kun Fun ^b,^*,^‡

PMCID: PMC3394059 PMID: 22798924

Abstract

In the title molecular salt, C₁₈H₂₄N₄ ²⁺·2PF₆ ⁻, the complete dication is generated by a crystallographic inversion centre. The central benzene ring makes a dihedral angle of 77.19 (9)° with each of the imidazole rings. In the crystal, C—H⋯F interactions link the cations and anions into layers lying parallel to the bc plane. The hexafluorophosphate anion is disordered over two sets of sites in a 0.520 (11):0.480 (11) ratio.

Related literature

For the properties of imidzole derivates, see: Shargel et al. (2006 ▶). For related structures, see: Haque et al. (2010 ▶, 2011 ▶).

Experimental

Crystal data

C₁₈H₂₄N₄ ²⁺·2PF₆ ⁻
M _r = 586.35
Triclinic,
a = 8.5441 (5) Å
b = 8.6018 (5) Å
c = 9.5626 (6) Å
α = 67.913 (1)°
β = 77.928 (1)°
γ = 67.837 (1)°
V = 601.25 (6) Å³
Z = 1
Mo Kα radiation
μ = 0.29 mm⁻¹
T = 297 K
0.28 × 0.25 × 0.12 mm

Data collection

Bruker APEX DUO CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.925, T _max = 0.966
12274 measured reflections
3996 independent reflections
2968 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.170
S = 1.04
3996 reflections
228 parameters
21 restraints
H-atom parameters constrained
Δρ_max = 0.38 e Å⁻³
Δρ_min = −0.36 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812028966/hb6877sup1.cif

e-68-o2280-sup1.cif^{(24.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812028966/hb6877Isup2.hkl

e-68-o2280-Isup2.hkl^{(195.8KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812028966/hb6877Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3A⋯F1ⁱ	0.93	2.49	3.408 (10)	170
C4—H4A⋯F3ⁱⁱ	0.93	2.48	3.369 (11)	160
C5—H5A⋯F6ⁱⁱⁱ	0.93	2.32	3.211 (8)	159

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

RAH and SFN thank Universiti Sains Malaysia (USM) for the short-term grant (304/PKIMIA/6311123) and RU grants (1001/PKIMIA/811157), (1001/PKIMIA/813023). HKF thanks USM for the Research University Grant No. 1001/PFIZIK/811160.

supplementary crystallographic information

Comment

Substituted imidazole derivatives are valuable in the treatment of many systemic fungal infections (Shargel et al., 2006). Previously, we have reported crystal structures of para- xylyl linked bis-imidazolium salts with propyl (Haque et al., 2011) and benzyl (Haque et al., 2010) substitutions. In this report, we describe the crystal structure of a para-xylyl linked bis-benzimidazolium salt with ethyl substitutuents

All parameters in (I) are within normal ranges. The complete dication is generated by a crystallographic inversion centre. The central benzene ring (C7—C9/C7A—C9A) makes a dihedral angle of 77.19 (9)° with the imidazole rings (N1—N2/C3—C5 and N1A—N2A/C3A—C5A). The hexafluorophosphate anions are disordered over two sets of sites with the final refined occupancies of 0.52 (1):0.48 (1).

In the crystal, C3—H3A···F1ⁱ, C4—H4A···F3ⁱⁱ and C5—H5A···F6ⁱⁱⁱ (Table 1) interactions link the molecules into layers lying parallel to the bc-plane.

Experimental

To a solution of 1,4-bis((1H-imidazol-1-yl)methyl)benzene (1.00 g, 0.004 mol) in 15 ml of acetonitrile, 1-iodoethane (1.31 g, 0.008 mol) was added. The mixture was refluxed at 363 K for 24 h. The resultant white precipitate was filtered, washed with fresh acetonitrile (2 × 5 ml) and converted directly to its hexafluorophosphate counterpart by metathesis reaction using KPF₆ (1.67 g, 0.008 mol) in 40 ml of methanol/water. The white precipitates were collected, washed with fresh acetonitrile (2 × 3 ml) to give the product as a white solid (1.78 g, 67%). M.p 467–469 K. Colourless blocks were obtained by slow diffusion method of the salt solution by using diethyl ether and acetonitrile at room temperature.